Tube shield attachment



Aug. 11, 1959 L. R. WOODS TUBE SHIELD ATTACHMENT Filed Feb. 6, 1956 Laeov 1342p M005 INVENTOR. A/eaq- AeeJ/e; War/e/ e/z k.

United States Patent @fifice 2,899,670 Patented Aug. 11, 1959 TUBE SHIELD ATTACHMENT Leroy R. Woods, Whittier, Califi, assignor to International Electronic Research Corporation, Burbank, Cahfi, a corporation of California Application February 6, 1956, Serial No. 563,655

3 Claims. (Cl. 339-143) The invention relates to shielding holders for electronic components and has particular reference to an attachment by means of which the casing of a tube shield is attached to a base, the base being of some appropriate type in turn secured to the chassis on which the mechanism is mounted.

There has been considerable impetus within the past few years in connection with the improvement of tube shields of a type found particularly useful for the mounting of electronic tubes. More exacting performance requirements have forced the attention of tube shield manufacturers on the design and production of tube shields capable of more effectively shielding a mass of tubes in the electronic installation and also capable of easy attachment and removal without sacrificing effective performance. Tube shields heretofore employed, while being equipped with dependable attachment means, have been of such construction that the securing of the shield to the base in many instances is greatly impaired by the crowded condition within an installation or on occasions have been such that once installed and left in use they become difficult to remove without a partial dismantling of the system. This has given rise to servicing problems which have become a burdensome condition.

It is therefore among the objects of the invention to provide a new and improved tube shield attachment which is simple in construction and inexpensive to manufacture and install.

Another object of the invention is to provide a new and improved tube shield attachment which by reason of its structure and assembly is one, the parts of which cannot be easily damaged to the extent that employment of the attachment becomes diificult.

Still another object of the invention is to provide a new and improved tube shield attachment whereby the tube shield casing can for all practical purposes be easily applied to the base at any position of rotation of the casing with respect to the base without it being necessary for the service man to hunt for the proper position of one with respect to the other before the attachment is locked.

A still further object of the invention is to provide a new and improved tube shield casing and base combination which make firm engagement with each other to the end that the casing will not vibrate loose from the base even under conditicntions of severe vibration and which moreover makes a sutficiently tight and complete metal to metal contact that heat generated in the electronic component can be readily passed by conduction through the casing to the socket and thence dissipated in the chassis.

With these and other objects in view, the invention consits in the construction, arrangement and combination of the various parts of the device whereby the objects contemplated are attained, as hereinafter set forth, pointed out in the appended claims and illustrated in the accom panying drawings.

In the drawings:

Figure l is a side elevational View of the shield casing and base in assembled form shown in perspective.

Figure 2 is a longitudinal sectional view of the combination.

Figure 3 is a cross-sectional view taken on the line 33 of Figure 2.

In the embodiment of the invention chosen for the purpose of illustration there is shown a tube shield casing it mounted upon a base 11 which in turn is supported upon a chassis 12. A glass envelope 13 of an electronic tube is shown mounted on the base.

More particularly the base consists of a shoe 14 having ears 15 extending outwardly therefrom in a position adapted to lie flat upon the chassis where the base can be secured by appropriate screws 16. The specific means of attachment of the base to the chassis will of course depend upon particular conditions encountered in a given installation. A socket 17 forms part of the base and within the socket is an appropriate plug of a substantially conventional sort adapted to receive the base of any one of a great variety of conventional electronic tubes. On one side side of the socket and near the outer end thereof is a projecting configuration 18 which for convenience and economy can be made of a pressed out portion of the material of the socket 17. In the chosen embodiment the configuration has a button-like appearance arcuate at the base and having a height preferably very slightly exceeding the thickness of the casing it).

The casing 10 in the chosen embodiment has a some what elongated cylindrical wall 39, an outer end of which includes an inwardly extending annular flange 20 providing a central opening 21. As noted the length of the casing is somewhat greater than the over-all height of the glass envelope so that if need be a spring 22 may be employed having its largest coil retained beneath the flange 26 and its smallest coil bearing downwardly upon the upper end of the glass envelope. The diameter of the inner circumference of the wall 19 is slightly larger than the exterior of glass envelope, thereby to provide an annular space 23 between the glass envelope and the wall.

An inner end 25 of the casing has an inside diameter the same as or perhaps slightly smaller than the outside diameter of the socket 17. A snug sliding fit between the inner end 25 of the casing and the socket is made possible by providing in the casing a plurality of slots In the chosen embodiment five such slots have been used. Each slot is identical and has oblique walls 27 at the open end of the slot providing an entrance opening 2%) somewhat wider at the mouth than the greatest dimension at the base of the configuration 18. Intermediate ends of each of the slots 26 is an enlargement 29, the circumference of which is substantially equal to the circumference at the base of the configuration 13. The center of each of the enlargements 29 is located a distance from the inner end 25 of the casing such that when the configuration is received in the enlargement, the casing will be in its proper preferred position on the base.

By making the slots 26 sufficiently long as suggested in the drawing, a springiness is provided in the areas of material between the slots so that these areas can spread slightly when the casing is pressed over the socket. A large area of contact, however, is advantageous and for that reason there is not provided any marked difference in diameters between the inner wall of the casing and the exterior wall of the socket.

When the casing is applied to the base, it need be rotated only slightly until some portion of the entrance opening 28 lies adjacent the configuration 18. Further pressure upon the casing will cause it to rotate slightly until the configuration is in alignment with the slot 26, at which point the immediately adjacent areas at the side of the slot 26 may spread slightly to permit passage of the configuration 18 until the configuration is received within the enlargement 29. At this point the adjacent areas will contract by reason of their inherent resiliency and the configuration will thereafter retain the casing upon the socket and the base. Only one configuration is necessary by reason of an appropriate fit of the casing around the socket. When the casing is to be removed it is necessary only to pull endwise on the casing, in which event the configuration Will again spread the areas at the sides of the respective slot, thereby permitting the casing to be withdrawn.

It will be apparent from the description that hunting for the proper connection between the casing and the base is minimized by providing only one configuration on the base and a multiplicity of slots on the casing. The

attachment provided takes up no more room than the casing itself and both parts which ultimately engage each other are of such construction that rough use and mishandling will not damage their effectiveness. The arrangement furthermore is such that an interior space is left within the casing surrounding the glass envelope for any one of a number of related mechanisms or attachments which might be employed with the casing.

While I have herein shown and described my invention in what I have conceived to be the most practical and preferred embodiment, it is recognized that departures may be made therefrom within the scope of my invention, which is not to be limited to the details disclosed herein but is to be accorded the full scope of the claims so as to embrace any and all equivalent devices.

Having described my invention, what I claim as new and desire to secure by Letters Patent is:

1. A tube shield mounting comprising a base having a chassis contacting portion and attachment means thereon, a substantially cylindrical socket member on the base, a substantially cylindrical casing member adapted to extend around and above an electronic tube, said casing member having a socket-engaging open end adapted to fit about said socket member with a snug sliding fit, one of said members having a protruding configuration on the side wall thereof, the other of said members having a plurality of circumferentially spaced open slots extending inwardly from an end edge, said slots having portions at ends thereof adjacent the open end of the member spreading progressively outwardly toward the end edge and having enlargements no greater in transverse dimension than the corresponding dimension of said configuration intermediate outer and inner ends whereby when one said member is forced over the other said member engagement of one of said slots with said configuration is adapted to guide said members to a position wherein said configuration projects into engagement with the wall of the enlargement of the respective slot.

2. A tube and shield assembly comprising a base having a chassis contacting portion, and attachment means thereon, a substantially cylindrical socket adapted for the reception of an electronic tube and a tube in said socket, a protruding configuration on the side wall of said socket, a substantially cylindrical casing adapted to extend around and above the electronic tube, said casing having a socket-engaging open end adapted to fit over said socket member with a snug sliding fit, said open end having a plurality of circumferentially spaced slots extending inwardly from the end and forming therebetween a series of elongated resilient members, said slots having enlargements comparable in size to said configuration intermediate outer and inner ends whereby when said casing member is forced over the socket member engagement of one of said slots with said configuration is adapted to spread adjacent resilient members and to guide said casing member to a position wherein said configuration projects into the enlargement of the respective slot and releases said resilient members for engagement with said socket member, and spring means between the tube and the cylindrical casing in a direction pressing the wall of the respective enlargement snugly against the configuration therein.

3. A tube and shield assembly comprising a base having a fiat chassis contacting portion, laterally extending ears having attachment means thereon, an upstanding substantially cylindrical socket adapted for the reception of an electronic tube, a tube in said socket and a rounded protruding configuration on the side wall of said socket, a one part substantially cylindrical casing of drawn sheet metal adapted to extend around and above the electronic tube at a distance laterally spaced therefrom, said casing having a socket-engaging open end adapted to fit over said socket with a snug sliding fit, said open end having a plurality of relatively wide circumferentially spaced slots extending inwardly from the end and forming a corresponding number of elongated resilient members, said slots having progressively expanding wide entrance portions at ends thereof adjacent the open end of the casing and having enlargements no greater in transverse dimension than the transverse dimension of said configuration intermediate outer and inner ends and at a location more nearly adjacent the outer ends whereby when said casing is forced over the socket engagement of the walls of one of said slots with said configuration is adapted to spread adjacent resilient members of the casing and guide said casing to a position wherein said configuration projects into the enlargement of the respective slot and said resilient members are released for spring-pressed engagement with said socket, and spring means between the tube and the cylindrical casing biased against the casing in a direction pressing the wall of the enlargement snugly into engagement with the configuration.

References Cited in the file of this patent UNITED STATES PATENTS 2,037,620 Dewhurst et a1. Apr. 14, 1936 2,453,172 Wilkie Nov. 9, 1948 FOREIGN PATENTS 455,325 Canada Mar. 22, 1949 622,075 Great Britain Apr. 26, 1949 

